Graphene and Gold Make a Better Brain Probe

Medical Design Briefs INSIDER

The flexible neural electrodes minimize tissue damage while still transmitting clear brain signals. (Credit: Daegu Gyeongbuk Institute of Science & Technology)

Electrodes placed in the brain record neural activity and can help treat neural diseases like Parkinson’s and epilepsy. Designing smaller, gentler electrodes that still pick up brain signals is a challenge because brain signals are so weak. Typically, the smaller the electrode, the harder it is to detect a signal. A team of researchers has developed a new probe that is small, flexible, and reads brain signals clearly. Using a combination of graphene and gold, the flexible neural electrodes minimize tissue damage while still transmitting clear brain signals.

The probe consists of an electrode, which records the brain signal that travels down an interconnection line to a connector. The connector transfers the signal to the machines measuring and analyzing the signals. The electrode starts with a thin gold base. Attached to the base are tiny zinc oxide nanowires, which are coated in a thin layer of gold, and then a layer of conducting polymer called PEDOT. When combined, these materials increase the probe’s effective surface area, conducting properties, and strength of the electrode, while still maintaining flexibility and compatibility with soft tissue.

Packing several long, thin nanowires together onto one probe enables the scientists to make a smaller electrode that retains the same effective surface area of a larger, flat electrode. This means the electrode can shrink, but not reduce signal detection. The interconnection line is made of a mix of graphene and gold. Graphene is flexible, and gold is an excellent conductor. The researchers tested the probe and found that it read rat brain signals very clearly and much better than a standard flat, gold electrode.

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